Automatic load-release coupler



March 15, 1960 K. F. CANNON, JR 2,928,693

AUTOMATIC LOAD-RELEASE COUPLER Filed Oct. 24, 1956 3 Sheets-Sheet 1 FIGJ. N3

INVENTOR K. F. CANNON JR.

March 15, 1960 K. F. CANNON, JR 2,928,693

AUTOMATIC LOAD-RELEASE COUPLER File d Oct. 24, 1956 s Sheets-Sheet 2 2s I r 24 z I M 94 7 I I 8 W 80 8'- W T E T 72 74 INVENTOR Q K. NNON JR.

W4 ATTORN Y5 March 15, 1960 K. F. CANNON, JR

AUTOMATIC LOAD-RELEASE COUPLER Filed Oct. 24, 1956 3 Sheets-Sheet 3 FICA.

INVENTOR K. F. CANNON JR.

BY I 545 ATTORN Y5 United States Patent F The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to a tension type release coupler and more particularly to a coupler for automatically releasing a load suspended thereby upon deposition of the load. More specifically, the coupler of this invention has applications in subaqueous operations such, for example, as the deposition of mines or submarine measuring instruments on the ocean fioon Previous devices of this character employed releasing pistols, explosively loaded weak links, and the pelicantrip hook devices. Such arrangements are complex, negative in action, destructive, and incur the extra expense of expended parts. Moreover, use of the explosive type is dangerous.

The present invention contemplates the provision of a novel coupler to release an object from a cable or other securing means used as a lifter or carrier. The coupler acts as a positive couple until the object, suspended from it, is supported so as to relieve the tension on the device. When the tension is relieved, the device releases its hold to thereby free the cable. In this manner, if the coupler is used for subaqueous operations, the coupler attached to the cable is retrieved and no parts of the coupler are lost other than. the load supporting tie-bar or shackle which is retained within the coupler during the lifting, carrying, and depositing operations.

An object of the invention is to provide a coupler which lockingly retains a load supporting shackle while under tension of the load and to automatically release the load shackle upon alleviation of the tension, as by deposition of the load.

Another object of the invention is the provision of an automatic release coupler in which spherical means lockingly retain a load supporting tie-bar while under tension of a load and to automatically release the load upon deposition thereof.

Another object is to provide an automatic release coupler for subaqueous operations in which no parts are expended upon discharge of the lead.

A further object is to provide an automatic release coupler which is simple in construction, dependable in operation, and reusable indefinitely.

These and various other objects of the invention will become apparent to those skilled in the art from the following description which will be amplified, in order to facilitate a better understanding, by reference to the appended drawings, in which: Fig. 1 is an isometric view, partly in section, of one embodiment of the invention adapted for use with a shackle type load support and showing the parts in load locking position in preparation for the load lifting operation; V

Fig. 2 is a fragmentary isometric view, partly in section, of Fig. 1 rotated 90 degrees about its longitudinal axis; j

Fig. 3 is a cross-sectional view taken along line 3- -3 of Fig. 1 and shows the elements in load retaining position;

Fig. 4 is a fragmentary cross-sectional View taken along line 4--4 of Fig. 3;

Fig. 5 is the cross-sectional view of Fig. 3 showing the elements in open or load releasing position;

Fig. 6 is a cross-sectional view taken along line 6-6 of 'Fig. 7 of another embodiment of the invention adapted for use with an enlarged-end type of load support; and

Fig. 7 is a cross-section taken along line '77 of Fig. 6. Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Figs. 1, 2, 3, 4 and 5, which illustrate a preferred embodiment of the invention, an automatic load-release coupler, denoted generally as 10, securely attached toan eye-bar 12 as by threads 14 and a cotter pin 15, the eye-bar being adapted to be secured to a lifting device. or hoisting crane by means of a hook or cable passing through eye 13. The eye-bar 12 has an enlarged backing-plate portion16 defining a planar face 18 to limit the upward longitudinal movement of a cup-shaped member or housing portion,

indicated generally as 20 and consisting of a cylindrical sleeve 22 having at one end a closure plate 24 with an axial bore circumferentially bounded by an annulus 26 of planar face 28, faces 18 and 28 abutting to limit the upward movement of cup 20 as is more clearly shown in Fig. 5. a 7

The basic member of the coupler 10 is an elongated piece having a main cylindrical bifurcated body portion 30 with two forks 31 and 32 defining a notch, or longitudinal-recess, 34 for receiving a load shackle or load supporting linkage 35, and a cylindrical, axially aligned shaft 36 extending from the other end of body portion 30 and being threadedly secured within enlarged portion 16. An annular flange 38, formed on body portion 30, serves as a bearing guide for the walls of sleeve 22 with the shaft 36 serving as a bearing guide for the bore of closure plate 24. i

An expansible spring 40 is axially disposed over body 30 and seated on flange 38, the other end of spring 40 abutting against closure plate 24 whereby cup-shaped member 20 is urged in the upward position with faces 18 and 28 in abutment under no load conditions as shown in Fig. 5.

A pair of equally dimensioned bores 42 and 44 are diametrically disposed on forks 61 and 32 respectively to receive balls 46 and 48 respectively, the balls having a diameter slightly less than the diameter of the bores 42 and 44 for crosswise or transverse movement in body portion 30. V I

A gradually decreasing internal perimeter portion 49, of sleeve 22, terminates in a uniform flange 50 which has an annular shoulder 51 formed thereon. The action of portion 49 is to inwardly displace balls 46 and 48 when cup-shaped member 20 is in the spring constrained position and frictionally interlocks with the balls 46 and 48 under load supporting conditions by virtue of the radially exerted forces by balls 46 and 48 from shackle 35 as shown in Figs. 2 and 3. The shoulder 51 serves to prevent external emergence of balls 46 and 48 under no-load conditions as shown in Fig. 5. When the cupshaped member 20 is in the spring constrained position, the internal face 53 of closure plate 24 is insubstantial abutment with the rear face 55 of body portion30 to thereby limit the longitudinal'travel in the lower direction of cup-shaped member 20. a

A key 58 has a locking shaft 59 which is adapted to be inserted in a bore 60 in cylindrical shaft 36 to maintain the coupler in locking position until the lifting operation is commenced whereupon sleeve 22 is frictionally Patented Mar. 1960 3 .l interlocked by balls 46 and 48 to retain cup-shaped member 20 in the lower position at which time key 58- is removed.

,The crossrsection ofrnoftch 34 and the diameters of balls 46 and 48 are selected such that the balls cannot drop out by way of notch 34 when a load shackle is not present in notch 34. Also, the. strength: of spring 40, is selected commensurate with the type of loads to' be lifted and deposited. V J V In operation, the coupler is normally in theposition shown in Fig. S'When being prepared to receive a load shackle. A load shackle is then inserted in, notch 34, as shown by dotted shackle 35a in Fig. 5, and the cupshaped member is pulled down. toits lowermost position to inwardly displace balls 46 and 48'whereby the cross-sectionof notch 34 is constricted, the coupler being maintained in this cocked; position by insertion of key 58 in bore 60 as shown in Fig. 3. Upon application of a load force, as by lifting the load, the cup s'haped member is retained in the lowermost position by the.

frictional'interlocking function of balls 46 and 48 with 7 decreased perimeter portion 49, as afored'escribed, and key 58 is thenremoved. After the load is' transported" to its desired locale, it is deposited. During thedeposition of the load, the load forces are alleviated sufficiently to enable the spring 40 to drive cup-shaped member 20 to itshpperniosf position, and the residual alleviated load embodiment suitable for "a loadtie-bar 70 .havingan l enlargedgend .72. This arrangement utilizes "a coaxial bore entering the, end of'body-portion and extending part way therethrough so 'asto be circumferentially bounded by cylindrical walls 74 of body portion 30'1to' define a longitudinal recess 75. Four equally dimen-i sioned bores 76, 78, 80 and 82, having coplanar axes are formed in the walls 74 for freely supporting balls 86, 88, 90, and 92, respectively, of equal-diameters slightly less than the bores. The internal diameter of recess 75 and of balls 86, 88, 90 and '92 are so chosen that the balls cannot drop out by way of' recess75', external emergenceof the balls being prevented by shoulder'sl. as described with respect to Fig; 5. The operation of the embodiment of ;Figs. 6'and 7 i's'simila'r to the embodif ment of Figslto 5. In lieuoffou'r balls, any nulrnher of balls may-be, utilized in Figs, 6 and 7.

Although the dimensionsin Fi'g's.'6 and 7 ar'es'uch' as topi'eventthe balls fronrdropping out'throu'gh recess 75',

thereover as sleeve 22 rides upwardly upon deposition of the load.

To adapt the couplerior subaqueous operations, a pair apertures64 and'66 ar'e fonnedain the side-walls, of sleeve 22.10 enable entry of waterinto; the-"spring:

retaining chamber to thereby-substantially equalize 'thein'ternaland external water pressure .on thecoupl'erunit so that the expansible operation of spring -:i'snot "ad versely affected by water pressure on the exterior 'sur face of the coupler unit. 7

' Obviously, many modificationsand variationsi of the present invention arepossible in the light ofihe above teachings It is thereforeto'befunderstood, that within the slcopefof the teachings herein and the aspen ed s (the invention may be raictiaeaotarwne than as? specifically described. i i

d seases additional means, such as a 'resili'e'nt 'annnlar band; 94 securely positioned to;o'verlap th'e'tr'ansver se bores, may

4 What is-claimed as new and desired to be secured by Letters Patent of the United States is:

1. A tension-locked, self-release coupler comprising an elongated piece having a shaft portion adapted to be 5 secured to a lifting device anda cylindrical bifurcated body portion defining a recess. between the forks of said bifurcated body portion for receiving a load-supporting linkage,geach of said forks having a bore mutually diametrically disposed, a spherical element freely supported in, each of said bores; a sleeve" substantially coextensive with said body portion and mounted thereover for longitudinal movement thereon, said body portion limiting the movement in one direction of said sleeve, the walls retainedin said recess, said sleeve being longitudinally 2 movable to a limited position in'ia direction opposite to said one'direction, a shoulder of increased perimeter on said sleeve in registry with said spherical elements when said sleeve is in said limited opposite direction and e'ifective' to enable, outward protrusion of said elementswhile simultaneously preventing external emergence of said elements from their respective bores, the cross-sec tionof sa'idrece'ss and the diameters of thesph'erica'l elements being such that the elements' are'u'nable to drop out; or the bores by way ofsaid recess and' an expansible spring supportedat one end by s'aid body portion and at the other end by aid sleev for driving said leeve to said limited opposite positionuin the absence of a load rqree, the-presence of a load rorcean & and linkage retained in said recess by the spherical elements when radial force on said reduced portionthat fr ict'iona'lly' bindssaid sleeve and prevents movement thereof until the" loa'dfor'ce is; alleviated during deposition of theload whereupon said" spring drives the. sleeve to 'saidlimited opposite position, the residual "alleviated load stresses forcing said spherical elements to move and protrude v outwardly whereby the load linkage is automatically released. 7

' 2. Ihe'fconpl'er of claim 1 wherein said sleeve is a enp shaped member invertedly mounted over said body portion and having aj'bore in the base thereof for slidab1e h evemefir on s'ai'd shaft b tidni 3 The' jcolipler'fof data 2, further including pressure etinaliizing'means to adapt the coupler for 'suba'queous' operations and comprising a' plurality of ports; in the sidewalls of saidcup-shaped member tov permit entry awa e-r th'e'rev'vithink V V V The coupler of claim 2,?vvl1'e'riein1said bores are of equaltdia'met er and said spherical elements are of equal diameter bur er a diameter-lesst'han'the diameter of said bores and further, including an annulargflange on said bod fportion, raid spring being supported between said fiange and the base of said cup-shaped member, and manually. operablejrneansincludingga key ins'ertable in a keyhole. in said shaftfpfortion forlocliingTsa'id cupshaped member-in the liniitediposition in said one direcv M J p, v g l'bo dy-por titih supported by, said-shaft portion atone end. thereof and having a longitudina'l recess erteringtnr'mi' nthe other end tliereof and extendin'g'part way 'sa'idbody for receivinga load supporting linkage, a pluralityv of bores sa'i'd recess, a ball freely supportdin each 'of 'sa'id bores, an annular flange, on saidbodyportion, a cup shaped ieli ss smisl y. extsns wi h i w aperture in the base of said cup-shaped member, said cup-shaped member being mounted over said body pormannered b)? said sleeve ceus'ing s'aidelementsto exert a in's'aid body portion, in tranversejommn idano with tion for longitudinally slidable movement on said flange and on said shaft portion by the walls thereof and by said aperture respectively, longitudinal movement in one direction of said cup-shaped member being limited by abutment of the base thereof with said one end of said body portion, the lip of said cup-shaped member having an annulus of decreased internal perimeter, the walls of said cup-shaped member having a concave annular portion adjacent said annulus, said concave portion contacting said balls when said cup-shaped member is in a substantially limited position in said one direction to thereby constrict the distance between the balls whereby a load supporting linkage is retained in said recess, stop means associated with said shaft portion for limiting movement of said cup-shaped member in a direction opposite to said one direction, an annular shoulder of increased internal perimeter formed on said annulus and in registry with said balls when said cup-shaped member is in said limited opposite direction, said annulus being efiective to enable outward protrusion of said balls while simultaneously preventing external emergence of said balls from their respective bores, the cross section of said recess and the diameters of the balls being such that the balls are unable to drop out of the bores by way of said recess, and an expansible spring supported at one end by said annular flange with the other end thereof abutting the base of said cup-shaped member for driving said cup-shaped member to said limited opposite direction in the absence of a load force, the presence of i a load force on a load linkage retained in said recess by said balls, when constricted by said cup-shaped member causing said balls to exert a radial force on said concave annular portion that frictionally binds said cupshaped member and prevents movement thereof until the load force is alleviated during deposition of the load whereupon said spring drives the cup-shaped member to said limited opposite direction, the residual alleviated stresses forcing said balls to move and protrude out.-

7. The coupler of claim 5, wherein said recess is a longitudinal notch bounded by opposing walls formed integrally with said body portion and being adapted to receive a shackle type of load linkage, said transverse bores being diametrically disposed in said opposing walls, said transverse bores being of equal diameter and said balls being of equal diameter but of a diameter less th said transverse bores.

8. An automatic load-release coupler comprisingan elongated piece having a shaft portion adapted to bea ball freely supported in each of said bores,- an annular flange on said body portion, a cup-shaped member substantially coextensive with said body portion and the forks and mounted thereover for slidable movement on said flange, said body portion limiting the movement in one direction of said cup-shaped member, the walls ofsaid cup-shaped member having a portion of decreasing internal perimeter, said decreasing portion contacting said balls when the cup-shaped member is in a substantially limited position in said one direction to thereby compress the distance between the balls whereby a loadshackle is retained in said recess, stop means associated with said shaft portion for limiting movement of said cup-shaped member in a direction opposite to said one direction, a shoulder on said cup-shaped member for preventing external emergence of said balls from their respective bores when said cup-shaped member is in said limited opposite direction, the space between said forks and the dimension said decreasing portion that frictionally binds said cupshaped member and prevents movement thereof until the load force is reduced upon deposition of the load to thereby release said radial force and permit said spring to drive the cup-shaped member tov said limited opposite direction whereby said load shackle is automatically released.

References Cited in the file of this patent UNITED STATES PATENTS 2,562,459 Hoey L. July 31, 1951 2,693,980 Heidman Nov. 9, 1954 2,729,495- Dejean Jan. 3, 1956 Benson etal. June 18, 1957 

